This proposal requests $250,000 to purchase an NMR spectrometer to be dedicated to 13C spectroscopy for a group of five users comprising synthetic organic, bioorganic, and bioinorganic chemists. The research conducted by this group includes synthesis of biologically active substances (prostaglandins, leukotrienes, thromboxanes, blood group substances, immunostimulators, antibiotics, proteins, sugars, hormones, nucleic acids), determination of structure of natural products and synthetic intermediates, examination of biological pathways and intermediates (shikimate, chorismate, phosphorylations; enzyme substrate complexes), and characterization of enzyme prosthetic groups (iron-sulfur and iron-molybdenum-sulfur complexes). The spectrometer requested will be used to provide sensitive and rapid identification of chemical species involved in these studies.